Chicago media reported Monday that the city’s bike-share system will not launch this year as planned, but will instead wait until next spring.

The justification for the delay is one that would be familiar to some New Yorkers, who are still waiting for their own bike-share program to begin operation. A city spokesman told the Chicago Sun-Times that officials want to make sure the program is working properly before opening it up to the public.

At the same time, Boston officials are marking a different kind of milestone. City leaders on Wednesday celebrated the expansion of its Hubway bike-share system, announcing new sharing stations in Cambridge, Brookline, Somerville and Boston proper, which will expand the whole system to 111 sharing stations and 1,100 bikes by the end of the riding season.

All three cities share a bike-share vendor: Alta Bicycle Share, the Oregon-based contractor that has helped to expand Montreal’s Bixi bike system to cities around the country.

But in New York and Chicago, as in Chattanooga, Tenn., Alta is trying to launch successful bike-sharing programs with newly developed operating software — a program the company and its Montreal-based partner, PBSC, turned to after severing ties with 8D Technologies, the firm that supplied the software for its successful operations in Montreal, Washington D.C., Denver and Boston, among others.

New York City officials and Alta representatives have revealed little about their plans or the specific cause of their delay. Spokesmen for both didn’t respond to an email seeking comment Wednesday.

But for 8D Technologies, which has filed a $26 million suit against PBSC over its exclusion from new installations of the Montreal system, the contrast is clear.

In cities like Boston that used the tried-and-true technology 8D offered, bike-share systems have proved effective and popular. In the few cities that have tried to install PBSC’s new technology, including New York and Chicago, delays have held up the launch of the program. (Chattanooga’s bike-share system, originally slated to launch in April, debuted late last month.)

“With all the problems and the delays in Chattanooga and then NYC, the delay in Chicago was in my opinion to be expected,” wrote Isabelle Bettez, 8D’s president and CEO, in an email. “As for Boston, their bike share scheme is using 8D’s technological solution, which is a great success over there, and expanding, as are most of the cities that have a bike share scheme based on 8D’s solution.”

In the Sun-Times, a city spokesman said the problem in Chicago was not a software delay, but did not go into specifics.

In a previous interview with the Journal, Bettez had worried that PBSC and Alta’s attempt to develop a new operating system while launching high-profile bike-share programs in major cities could lead to glitches and delays — and in the process damage the image of a transportation concept that has so far proved popular in cities in Europe, the U.S. and Canada.

New York officials hoped to launch the Citi Bike in time for users to enjoy much of the summer, but now will not specify a new target date. Chicago’s struggle indicate a risk New York now runs – rather than launch a major priority of Mayor Michael Bloomberg’s as the weather begins to turn, will New York also have to wait for spring?

The scale is larger here: Chicago’s system was to launch with 3,000 bikes this summer; New York was to being with 6,000 this summer, rising to 10,000 next year.

So far, Mayor Michael Bloomberg is dismissive of concerns, and neither the mayor nor Transportation Commissioner Janette Sadik-Khan has said if they will force Alta to pay for missing its contractual deadline of July 31 to launch the first phase of the bike-share program.

Meanwhile, the Montreal Gazette reported Wednesday that PBSC, which has received millions in financing from the city of Montreal, has declined to answer questions about its finances.